a) Field of the invention
The present invention relates to a camera shutter device incorporated with lens shifting mechanism using a motor as driving power source.
b) Description of the prior art
In some of the so-called autofocus type compact cameras, the shutter devices are incorporated with lens shifting mechanisms for autofocus by integrating the shutter blocks with the lens barrels for compact designs of the cameras, etc. These cameras use stepping motors or electromagnetic actuators as the driving power sources for lens shifting as well as the shutter opening and closing operation. The shutter devices incorporated with lens shifting mechanisms are classified into the set type and the setless type, both of which perform two kinds of operations, i.e., the lens shifting operation and the shutter opening and closing operation with a single driving power source, thereby posing the problems described below.
The set type shutter device requires a complicated mechanism, a large setting force and a long setting stroke. On the other hand, the setless type shutter device, for which a simple mechanism is sufficient, requires a magnet device in addition to an actuator adopted as the driving source, thereby complicating operating sequence thereof.